Funny vegetable, you say to yourself!
It has a good head, goes through several colors (red, green, white) and comes in multiple varieties. It even seems to have been so omnipresent in the pots of our ancestors that a number of expressions have kept traces of it, among which this one does not seem the least mysterious to you.
" Stupid as cabbage", "to be in the cabbage", "to make one's cabbage fat from something" (to fatten one's cabbage is to take advantage of something), "to spare the goat and the cabbage"... not to mention all the expressions which were still in use in the 19th century and which have since disappeared (“going through cabbage”, “thundering over cabbage”, “rowing cabbage”, etc.).
In “cabbage”, on the other hand, the existence of said vegetable is strongly questioned.
Indeed, the expression which appeared in the 18th century, with the meaning of "to suffer a failure, not to succeed", would perhaps come from the game of skittles where one said "to make a white blow" when one does not felled none.
“White Choup” would be the Berry version, which would have been reinterpreted as a “white cabbage” which, if it seemed a little comical, nevertheless had the merit of being a limpid form for everyone.
Skeptics will still be able to venture down another path and note, even if this does not provide the key to the expression, that in "failing" there is cabbage...
Price
€23.55